Audio signal processing apparatus

Abstract

An audio signal processing apparatus is provided. The audio signal processing apparatus comprises a clock generator, a processing module, an amplifying module and an output module. The clock generator is used for generating a clock signal. The processing module is coupled to the clock generator for processing the clock signal and generating a processing signal. The amplifying module is coupled to the processing module for amplifying the processing signal and generating an amplifying signal. The output module is coupled to the amplifying module for outputting the amplifying signal.

1. An audio signal processing apparatus, comprising:
 a clock generator for generating a clock signal comprising:
 a control interface for receiving a control signal; and 
 a clock synthesizer coupled to the control interface for generating the clock signal according to the control signal; 
 
 a processing module coupled to the clock generator for processing the clock signal and generating a processing signal; 
 an amplifying module coupled to the processing module for amplifying the processing signal and generating an amplifying signal; and 
 an output module coupled to the amplifying module for outputting the amplifying signal. 
 
     
     
       2. The audio signal processing apparatus of  claim 1 , wherein the clock generator further comprises an analog-to-digital converter, coupled to the control interface, for converting a DC voltage to the control signal. 
     
     
       3. The audio signal processing apparatus of  claim 1 , wherein the clock generator further comprises a crystal oscillator, coupled to the clock synthesizer, for generating a reference frequency, wherein the clock synthesizer generates the clock signal according to the reference frequency. 
     
     
       4. The audio signal processing apparatus of  claim 1 , wherein the processing module comprises:
 a rectifier for rectifying the clock signal to obtain a rectified signal; and 
 regulator coupled to the rectifier for regulating the level of the rectified signal and generating the processing signal. 
 
     
     
       5. The audio signal processing apparatus of  claim 1 , wherein the amplifying module comprises:
 a first modulator, coupled to the clock generator and the processing module, for generating a first modulated signal by modulating an audio input signal and the processing signal according to an input clock; 
 a second modulator, coupled to the clock generator and the processing module, for generating a second modulated signal by modulating the audio input signal and the processing signal according to the input clock; 
 a control switch, having one terminal selectively coupled to the first modulator and the second modulator, for switching between the first modulator and the second modulator, thereby outputting the first modulated signal and the second modulated signal in response to a switch control signal; and 
 an output stage circuit, coupled to another terminal of the control switch, for amplifying the first modulated signal and the second modulated signal and generating the amplifying signal. 
 
     
     
       6. The audio signal processing apparatus of  claim 5 , wherein the first modulator is a fixed clock pulse width modulator (PWM). 
     
     
       7. The audio signal processing apparatus of  claim 5 , wherein the second modulator is a sigma-delta pulse modulation pulse width modulator (PWM). 
     
     
       8. The audio signal processing apparatus of  claim 5 , wherein the control interface of the clock generator outputs the input clock to the first modulator and the second modulator. 
     
     
       9. The audio signal processing apparatus of  claim 1 , wherein the amplifying module is a power amplifier. 
     
     
       10. The audio signal processing apparatus of  claim 1 , wherein the amplifying module is a class D audio amplifier. 
     
     
       11. The audio signal processing apparatus of  claim 1 , wherein the output module is a speaker.